Chloride-induced corrosion of concrete structures in marine areas is a serious problem and is generally affected by several factors. Chloride concentration is an important parameter for estimating the corrosion state of concrete. In this research, first chloride concentration at various depths of concrete specimens was measured using the accelerated chloride penetration test method under laboratory conditions, simulating a marine environment after 4·5 and 9 months. Then the obtained experimental dataset of 162 in 9 months of exposure was used to develop classification and regression trees (CARTs) and an artificial neural network (ANN) as subsets of artificial intelligence methods. Environmental condition, penetration depth, water-to-cementitious material ratio and silica fume mass were considered as input parameters, and chloride concentration was taken as the output parameter. Finally, results for the two methods were compared with the experimental observations to evaluate their accuracy in phases of training and testing. As a further aspect to the study, prediction of chloride concentration as a function of the exposure time and unavailable testing parameters was carried out. The results showed that ANN and CART have good ability and accuracy for predicting the chloride concentration in concrete under marine environment conditions. In the present research, the ANN method showed more accuracy.

In the present study, the performance of concrete sandwich panel against fire and axial load has been considered. A finite element model of a sandwich wall is presented and evaluated the performance under different temperature (200, 400, 600 °C. The ratio of width, thickness and length of wall are constant and the axial load enters on the top of wall. The maximum displacement and stress in different models shows the capacity of wall is increased at high temperature. The displacement has dramatically increased at temperature loading of 800 °C and it has gained which shows poor efficiency of wall at high temperatures.

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This study sought to investigate steel frames’ performance with dual lateral loader system (Frame bending + bracings of divergent and convergent) in near and far filed to fault. In order to this, four categories of steel frame with dual system with 8, 10 and 12 story are designed with average formation based on existing seismic regulation in 2800 standard of Iran and tenth chapter of national regulations of construction (planning and performing steel construction). Time history non-linear dynamic analysis under the effect of near and far field earthquakes has been done on plan’s models. Then the maximum of floors’ dislocation, floors’ drift, roof dislocation, base shear and energy curves of frames are shown and compared with each other. All non-linear time history analyses have been accomplished using PERFORM 3D software.